Seeing 2.4 GHz Radio Waves 43
szczys writes: There was this art piece that circled the internet a few weeks ago which used a tablet to visualize WiFi and other signals and it was complete fake. It was cool, and it approximated where radio waves emanated from, but it wasn't actually measuring them for display. Greg Charvat has built his career on Radar and other RF design. Seeing that demo he realized he could show you what actual microwaves look like. He used a radar that he built himself from coffee cans. By altering the circuit just a bit he is able to move the receiver around the room and illuminate different LEDs based on the signal traits. A long exposure photograph captures this and lets you see the radio waves. It's like a charcoal rubbing but for electromagnetic waves.
I'm coming mother (Score:3)
I didn't know Norman from Bates Motel was into radar and em waves. Cool.
Re: Can't wait for conspiracy theorists (Score:4, Interesting)
Re: (Score:2)
I've often wanted something that could produce an image from EM emissions, in the same way that our eyes create an image from light. One way to do so is to capture the electromagnetic field in an matrix in an area (say 2x2m^2), called an aperture, and converting these captured signals to visualise the sources of the signals, more or less like a scanning beamformer. In practice it would be costly to capture hundreds of signals at once. Assuming the sources are stationary, you can also scan the aperture horizontally and vertically.
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The output from an actual WiFi transmitter would be more interesting since almost all of them use mediocre antennas with weird radiation patterns and group delay instead of close to ideal horn antennas.
Re: OK, that's pretty damn nifty. (Score:2)
i see Dead People (Score:2)
I don't get it (Score:4, Funny)
What does this have to do with the new iPad Pro? This site is supposed to be news for nerds...not this boring gobbledygook!!
Re:I don't get it (Score:5, Insightful)
I actually think this is one of the most awesome things I have seen on slashdot in a long time.
Someone did a real science experiment with fifty bucks worth of parts and two coffee cans.
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Highest-modded whoosh i've seen on slashdot in a long time.
Cool, but it's been done better (Score:5, Interesting)
7 months ago on Hackaday's own site:
http://hackaday.com/2015/02/17/mapping-wifi-signals-in-3-dimensions/
not really what microwave would look like. (Score:4, Interesting)
Microwave and light wave are on the same spectrum so if you could see in microwave then it would just illuminate objects just like
regular light or ultraviolet light but with the awesome effect that it would actually penetrate some objects. A camera that shifted
microwave down to visible light would be really cool similar to how a ultraviolet camera lets you see ultraviolet light.
Re:not really what microwave would look like. (Score:5, Insightful)
A big difference from regular light would be blurriness. WiFi, at 2.5 GHz, has a wavelength of about 5 inches. This would lead to an extremely foggy, blurry image of everything around you.
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A big difference from regular light would be blurriness. WiFi, at 2.5 GHz, has a wavelength of about 5 inches. This would lead to an extremely foggy, blurry image of everything around you.
This is actually terribly insightful. I just googled "c / 2.4 Ghz" and Google came back with "12.4913524 centimeters".
Re: (Score:2, Interesting)
Fun fact, humans can actually see UV light pretty well if you remove our lens that obscures it.
Many people who have had one of their lenses removed have noticed it, and many have reproduced what it approximately looks like and how it affects the world they see around them.
Their sensitivity to bluer frequencies is still the same though, no increase in fidelity, just opens up more of the spectrum to see.
For the most part, it increased how vibrant everything looked, a whitish blue-violet filter being applied t
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Microwave and light wave are on the same spectrum so if you could see in microwave then it would just illuminate objects just like regular light or ultraviolet light but with the awesome effect that it would actually penetrate some objects. A camera that shifted microwave down to visible light would be really cool similar to how a ultraviolet camera lets you see ultraviolet light.
Maybe a "pinhole" microwave camera is possible?
Is this guy serious? (Score:1)
not waves (Score:2)
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